Not that any of them really care how rich they are, but Facebook's Mark Zuckerberg has overtaken both Google founders, Sergey Brin and current CEO Larry Page, in the latest Forbes 400 Rich List of the richest Americans.

Zuckerberg is the biggest climber too, he's more than doubled his net worth in the past year. Or course, all of his worth comes from his stake in Facebook and whichever way the company's value is headed so is Zuckerberg's fortune.

Sitting at the top of the richest Americans list is Bill Gates who, despite all his charity work, can't seem to lose money faster than he makes them.

Again, his worth is greatly linked to that of Microsoft, but the company is doing all right, if not exactly flying, in the stock markets.

Bill Gates is worth a cool $59 billion, 43.8 billion Euro, putting him well ahead of his buddy Warren Buffet who is listed with a personal fortune of $39 billion, 28.9 billion Euro.

At number three, with $33 billion, 24.5 billion Euro, sits Larry Ellison, the CEO and founder of Oracle, who has been spending his time in court these days with the other billionaire named Larry on the list, Google's CEO.

Larry Page is worth $16.7 billion, 12.4 billion Euro, from his stake in Google as much as Sergey Brin, the other cofounder of the internet behemoth.

Zuckerberg has just overpassed them with an estimated $17.5 billion, 13 billion Euro, fortune. That's from a Facebook valuation of $66.5 billion, 49.4 billion Euro, the company has been trading as high as $80 billion in the secondary markets.